GB1206021A - Process and cathode sheet for electrolytic refining of copper, nickel or zinc metal - Google Patents

Abstract

1,206,021. Electro-refining of copper, nickel and zinc. PHELPS DODGE REFINING CORP. Jan.5, 1968 [Feb. 15, 1967], No.903/68. Heading C7B. In a process for the electrolytic refining of copper, nickel or zinc using an anode of the impure metal and producing a cathode of pure metal, thin initial starting sheets of the metal, e.g. produced by electro-deposition of the metal on to mother sheets from which it may subsequently be stripped, are made the cathode is the electrolytic bath to deposit a layer of metal on both sides of the starting sheet until the sides have uniform characteristics and the sheets have become sufficiently annealed by the high temperature of the electrolytic bath to be cold worked; the intermediate cathode sheets thus produced are subjected to cold working in a press which exerts stressing forces on both sides of the sheet at adjacent loci over substantially the whole planar area thereof in a direction perpendicular to the plane of the sheet so that it is stressed beyond its elastic limit such as to give it a permanent set in a level condition; and then continuing electro-deposition on both sides of the pressed intermediate cathode sheets thus obtained until the sheets have sufficient thickness. The press used in the cold working of the sheets may be a platen press in which the faces of each platen are mounted with spherical balls extending outwards therefrom and offset from those extending from the opposing paten face, as described in Patent Specification 1,160,489. Prior to use as cathodes the starting sheets may be provided with a supporting loop 28, crimped edges 31, 31a and horizontal crimps 35 a-L.